1 #!/usr/bin/env python 2 3 """ 4 Translate the AST of a Python program into a more interpretable representation. 5 6 Copyright (C) 2007, 2008, 2009 Paul Boddie <paul@boddie.org.uk> 7 8 This program is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free Software 10 Foundation; either version 3 of the License, or (at your option) any later 11 version. 12 13 This program is distributed in the hope that it will be useful, but WITHOUT 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 15 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 16 details. 17 18 You should have received a copy of the GNU General Public License along with 19 this program. If not, see <http://www.gnu.org/licenses/>. 20 """ 21 22 from micropython.opt import Optimiser 23 from micropython.common import * 24 from micropython.data import * 25 from micropython.rsvp import * 26 from micropython.trans import Helper 27 import compiler.ast 28 from compiler.visitor import ASTVisitor 29 30 # Program visitors. 31 32 class Translation(ASTVisitor, Helper): 33 34 "A translated module." 35 36 # Attribute access instructions, for use with the appropriate handlers. 37 38 attribute_load_instructions = ( 39 LoadAddress, LoadAddressContext, LoadAddressContextCond, 40 LoadAttr, LoadAttrIndex, LoadAttrIndexContextCond 41 ) 42 attribute_store_instructions = ( 43 None, None, None, 44 StoreAttr, StoreAttrIndex, None 45 ) 46 47 # Name access instructions, for use with the appropriate handlers. 48 49 name_load_instructions = (LoadName, LoadAddress, None) 50 name_store_instructions = (StoreName, StoreAddress, StoreAddressContext) 51 52 def __init__(self, module, program): 53 54 """ 55 Initialise the translation with an inspected 'module' and the 'program' 56 container. 57 """ 58 59 ASTVisitor.__init__(self) 60 self.visitor = self 61 self.module = module 62 63 # Global program dependencies. 64 65 self.program = program 66 self.objtable = self.program.get_object_table() 67 self.paramtable = self.program.get_parameter_table() 68 self.importer = self.program.get_importer() 69 self.builtins = self.importer.modules.get("__builtins__") 70 71 # Optimisation. 72 73 self.optimiser = Optimiser(self, program.optimisations) 74 75 # The current unit being translated. 76 77 self.unit = None 78 79 # The temporary storage used by the current assignment expression. 80 81 self.expr_temp = [] 82 83 # Wiring within the code. 84 85 self.labels = {} 86 self.label_number = 0 87 self.loop_blocks = [] 88 self.exception_blocks = [] 89 self.in_exception_handler = 0 90 91 self.reset() 92 93 def __repr__(self): 94 return "Translation(%r)" % self.module 95 96 def reset(self): 97 98 "Reset the state of the translator." 99 100 # The code itself. This is limited to the code for a particular block 101 # being processed. 102 103 self.blocks = [] 104 105 # Information about temporary values. 106 107 self.temp_positions = set() 108 self.max_temp_position = -1 109 110 # Information about instructions which construct frames. 111 112 self.frame_makers = [] 113 114 # Optimiser state must be reset for each unit. 115 116 self.optimiser.reset() 117 118 def get_module_code(self): 119 120 """ 121 Return the top-level module code. 122 """ 123 124 self.unit = self.module 125 self.reset() 126 127 block = self.new_block() 128 self.set_block(block) 129 130 if self.module.module is not None: 131 self.dispatch(self.module.module) 132 133 # Finish off the translated program if appropriate. 134 135 if self.module.name == "__main__": 136 self.new_op(Return()) 137 138 self.unit.temp_usage = self.max_temp_position + 1 139 self.unit.blocks = self.blocks 140 return self.blocks 141 142 def get_code(self, unit): 143 144 "Return the code for the given 'unit'." 145 146 self.unit = unit 147 self.reset() 148 149 block = self.new_block() 150 self.set_block(block) 151 152 if unit.astnode is not None: 153 self.dispatch(unit.astnode) 154 155 self.unit.temp_usage = self.max_temp_position + 2 # include space for instantiators to expand backwards 156 self.unit.blocks = self.blocks 157 return self.blocks 158 159 def get_instantiator_code(self, cls): 160 161 "Return the code for the given class 'cls'." 162 163 self.unit = cls.get_instantiator() 164 self.reset() 165 166 block = self.new_block() 167 self.set_block(block) 168 169 init_method = cls.get_init_method() 170 171 # Make an object and store it in the unused first slot. 172 173 self.make_instance(cls, len(cls.instance_attributes())) 174 self.new_op(StoreTemp(0)) 175 176 # Invoke the appropriate initialiser. 177 178 self.new_op(LoadFunction(init_method)) 179 self.new_op(LoadCallable()) 180 self.new_op(JumpInFrame()) 181 182 # Store the object as the result. 183 184 self.new_op(LoadTemp(0)) # load the context from the locals 185 self.new_op(StoreResult()) 186 self.new_op(Return()) 187 188 self.unit.blocks = self.blocks 189 return self.blocks 190 191 # Visitor methods. 192 193 def default(self, node, *args): 194 raise TranslateError(self.module.full_name(), node, "Node class %r is not supported." % node.__class__) 195 196 def dispatch(self, node, *args): 197 return ASTVisitor.dispatch(self, node, *args) 198 199 # Concrete visitor methods. 200 201 # Binary operators. 202 203 visitAdd = Helper._visitBinary 204 visitBitand = Helper._visitBinaryBit 205 visitBitor = Helper._visitBinaryBit 206 visitBitxor = Helper._visitBinaryBit 207 visitDiv = Helper._visitBinary 208 visitFloorDiv = Helper._visitBinary 209 visitLeftShift = Helper._visitBinary 210 visitMod = Helper._visitBinary 211 visitMul = Helper._visitBinary 212 visitPower = Helper._visitBinary 213 visitRightShift = Helper._visitBinary 214 visitSub = Helper._visitBinary 215 216 # Unary operators. 217 218 visitInvert = Helper._visitUnary 219 visitUnaryAdd = Helper._visitUnary 220 visitUnarySub = Helper._visitUnary 221 222 # Logical operators. 223 224 def visitAnd(self, node): 225 end_block = self.new_block() 226 temp_pos = self.reserve_temp() 227 temp = LoadTemp(temp_pos) 228 229 for n in node.nodes[:-1]: 230 self.dispatch(n) 231 self.new_op(StoreTemp(temp_pos)) 232 233 self._generateTestBoolean(n, temp) 234 self.new_op(JumpIfFalse(end_block)) 235 236 self.dispatch(node.nodes[-1]) 237 self.new_op(StoreTemp(temp_pos)) 238 239 self.set_block(end_block) 240 241 self.new_op(temp) 242 self.discard_temp(temp) 243 244 def visitNot(self, node): 245 self.dispatch(node.expr) 246 247 temp = self.optimiser.optimise_temp_storage() 248 self._generateTestBoolean(node.expr, temp) 249 self.discard_temp(temp) 250 251 self.new_op(InvertBoolean()) 252 self._generateLoadBoolean(node) 253 254 def visitOr(self, node): 255 end_block = self.new_block() 256 temp_pos = self.reserve_temp() 257 temp = LoadTemp(temp_pos) 258 259 for n in node.nodes[:-1]: 260 self.dispatch(n) 261 self.new_op(StoreTemp(temp_pos)) 262 263 self._generateTestBoolean(n, temp) 264 self.new_op(JumpIfTrue(end_block)) 265 266 self.dispatch(node.nodes[-1]) 267 self.new_op(StoreTemp(temp_pos)) 268 269 self.set_block(end_block) 270 271 self.new_op(temp) 272 self.discard_temp(temp) 273 274 # Comparisons. 275 276 def visitCompare(self, node): 277 278 """ 279 _t1 = node.expr 280 _t1 op1 _t2 and _t2 op2 _t3 and ... 281 """ 282 283 end_block = self.new_block() 284 285 self.dispatch(node.expr) 286 temp2 = self.optimiser.optimise_temp_storage() 287 288 # NOTE: Replicated by some code in micropython.inspect.visitCompare. 289 290 last_op = node.ops[-1] 291 292 for op in node.ops: 293 op_name, next_node = op 294 methods = comparison_methods[op_name] 295 296 # Propagate the arguments as we traverse the construct. 297 298 temp1 = temp2 299 self.dispatch(next_node) 300 temp2 = self.optimiser.optimise_temp_storage() 301 302 # Use the appropriate mechanism, setting the boolean status for the 303 # comparison. 304 305 if methods is not None: 306 left_method, right_method = methods 307 308 # Generate method call using evaluated argument and next node. 309 310 temp_result = self._generateBinary(node, temp1, temp2, left_method, right_method) 311 self.new_op(temp_result) 312 self._generateTestBoolean(node, temp_result) 313 self.discard_temp(temp_result) 314 315 else: 316 # Deal with the special operators. 317 318 if op_name.startswith("is"): 319 self.new_op(temp1) 320 self.record_value() 321 self.new_op(temp2) 322 self.new_op(TestIdentity()) 323 self.set_source() 324 self.discard_value() 325 326 elif op_name.endswith("in"): 327 self.new_op(temp2) 328 329 # Get method on temp2. 330 331 self._generateAttr(node, "__contains__", self.attribute_load_instructions) 332 temp_method = self.optimiser.optimise_temp_storage() 333 334 # Add arguments. 335 # NOTE: No support for defaults. 336 337 self._startCallFunc() 338 self.new_op(temp2) 339 self.new_op(StoreFrame(0)) 340 self.new_op(temp1) 341 self.new_op(StoreFrame(1)) 342 self._endCallFuncArgs(2) 343 self._doCallFunc(temp_method) 344 self._endCallFunc(temp_method) 345 346 temp_result = self.get_temp() 347 self._generateTestBoolean(node, temp_result) 348 self.discard_temp(temp_result) 349 350 if op_name.find("not") != -1: 351 self.new_op(InvertBoolean()) 352 353 # Test the result and jump to the end block if false. 354 355 if op is not last_op: 356 self.new_op(JumpIfFalse(end_block)) 357 358 # Compilation duties... 359 360 self.discard_temp(temp1) 361 362 self.discard_temp(temp2) 363 364 # With the status set above, produce a boolean result. 365 366 self.set_block(end_block) 367 368 # Yield the appropriate value. 369 370 self._generateLoadBoolean(node) 371 372 # Expressions. 373 374 def visitBackquote(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Backquote") 375 376 def visitCallFunc(self, node): 377 378 """ 379 Evaluate positional arguments, evaluate and store keyword arguments in 380 the correct location, then invoke the function. 381 """ 382 383 # Mark the frame, evaluate the target, generate the call. 384 385 self._startCallFunc() 386 self.dispatch(node.node) 387 temp_target, target, temp_context = self._generateCallFunc(node.args, node) 388 self._doCallFunc(temp_target, target) 389 self._endCallFunc(temp_target, target, temp_context) 390 391 def visitConst(self, node): 392 const = self.importer.get_constant(node.value) 393 self.new_op(LoadConst(const)) 394 395 def visitDict(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Dict") 396 397 def visitEllipsis(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Ellipsis") 398 399 def visitExec(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Exec") 400 401 def visitExpression(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Expression") 402 403 def visitGenExpr(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "GenExpr") 404 405 def visitGenExprFor(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "GenExprFor") 406 407 def visitGenExprIf(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "GenExprIf") 408 409 def visitGenExprInner(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "GenExprInner") 410 411 def visitGetattr(self, node): 412 self._visitAttr(node, self.attribute_load_instructions) 413 414 def visitList(self, node): 415 self._generateList(node) 416 417 def visitListComp(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "ListComp") 418 419 def visitListCompFor(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "ListCompFor") 420 421 def visitListCompIf(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "ListCompIf") 422 423 def visitName(self, node): 424 425 # Handle names referring to constants. 426 427 if self.importer.predefined_constants.has_key(node.name): 428 const = self.importer.get_predefined_constant(node.name) 429 self.new_op(LoadConst(const)) 430 431 # Handle all other names. 432 433 else: 434 self._visitName(node, self.name_load_instructions) 435 436 def visitSlice(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Slice") 437 438 def visitSubscript(self, node): 439 self.dispatch(node.expr) 440 self._startCallFunc() 441 self._generateAttr(node, "__getitem__", self.attribute_load_instructions) 442 temp_target, target, temp_context = self._generateCallFunc(node.subs, node) 443 self._doCallFunc(temp_target, target) 444 self._endCallFunc(temp_target, target, temp_context) 445 446 def visitTuple(self, node): 447 self._generateTuple(node) 448 449 # Definitions. 450 451 def visitAssign(self, node): 452 453 """ 454 Evaluate the expression from the given 'node' and assign it to the 455 associated recipients. 456 """ 457 458 self.dispatch(node.expr) 459 460 # Record the value and then dispatch to the assignment targets. 461 462 self.record_value(self.has_immediate_usage(node.nodes)) 463 464 for n in node.nodes: 465 self.dispatch(n) 466 467 self.discard_value() 468 469 def visitAssAttr(self, node): 470 471 "Assign the assignment expression to the recipient 'node'." 472 473 self._visitAttr(node, self.attribute_store_instructions) 474 self.set_source() 475 476 def visitAssList(self, node): 477 478 """ 479 Assign items from the assignment expression to each of the recipients 480 found within the given 'node'. 481 """ 482 483 for i, n in enumerate(node.nodes): 484 self._startCallFunc() 485 self.new_op(self.expr_temp[-1]) 486 self._generateAttr(node, "__getitem__", self.attribute_load_instructions) 487 temp_target, target, temp_context = self._generateCallFunc([compiler.ast.Const(i)], node) 488 self._doCallFunc(temp_target, target) 489 self._endCallFunc(temp_target, target, temp_context) 490 491 # Provide a different source value. 492 # NOTE: Permitting immediate usage given that neither name nor 493 # NOTE: attribute accesses should involve a function call 494 # NOTE: overwriting the above result. 495 496 self.record_value(self.is_immediate_user(n)) 497 self.dispatch(n) 498 self.discard_value() 499 500 def visitAssName(self, node): 501 502 "Assign the assignment expression to the recipient 'node'." 503 504 if node.flags == "OP_DELETE": 505 raise TranslationNotImplementedError(self.module.full_name(), node, "AssName(OP_DELETE)") 506 507 self._visitName(node, self.name_store_instructions) 508 self.set_source() 509 510 visitAssTuple = visitAssList 511 512 def visitAugAssign(self, node): 513 use_binary_block = self.new_block() 514 end_block = self.new_block() 515 516 # Evaluate the expression. 517 518 self.dispatch(node.expr) 519 temp2 = self.optimiser.optimise_temp_storage() 520 521 # Evaluate the target. 522 523 self.dispatch(node.node) 524 temp1 = self.optimiser.optimise_temp_storage() 525 526 # Find the augmented assignment method and attempt to use it. 527 528 aug_method, (left_method, right_method) = augassign_methods[node.op] 529 temp_out = self._generateOpMethod(node, temp1, temp2, aug_method, use_binary_block, use_binary_block, end_block) 530 self.discard_temp(temp_out) # NOTE: Will re-use the same storage. 531 532 # Where no such method exists, use the binary operator methods. 533 534 self.set_block(use_binary_block) 535 temp_out = self._generateBinary(node, temp1, temp2, left_method, right_method) 536 537 # Assign the result to the name. 538 539 self.set_block(end_block) 540 self.new_op(temp_out) 541 self.record_value(1) 542 543 if isinstance(node.node, compiler.ast.Name): 544 self.visitAssName(node.node) 545 elif isinstance(node.node, compiler.ast.Getattr): 546 self.visitAssAttr(node.node) 547 else: 548 raise TranslationNotImplementedError(self.module.full_name(), node, "AugAssign(Slice or Subscript)") 549 550 self.discard_value() 551 552 # Compilation duties... 553 554 self.discard_temp(temp1) 555 self.discard_temp(temp2) 556 557 def visitClass(self, node): 558 if not node.unit.parent.has_key(node.unit.name): 559 return 560 561 # Store the name. 562 563 self.new_op(LoadClass(node.unit)) 564 self.record_value() 565 self._visitName(node, self.name_store_instructions) 566 self.set_source() 567 self.discard_value() 568 569 # Visit the code. 570 571 unit = self.unit 572 self.unit = node.unit 573 self.dispatch(node.code) 574 self.unit = unit 575 576 def visitDecorators(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Decorators") 577 578 def visitFrom(self, node): pass 579 580 def visitFunction(self, node): 581 if not node.unit.parent.has_key(node.unit.name): 582 return 583 584 # Only store the name when visiting this node from outside. 585 586 if self.unit is not node.unit: 587 self.new_op(LoadFunction(node.unit)) 588 self.record_value() 589 590 self._visitName(node, self.name_store_instructions) # AssName equivalent 591 self.set_source() 592 self.discard_value() 593 594 self._generateFunctionDefaults(node.unit) 595 596 # Visiting of the code occurs when get_code is invoked on this node. 597 598 else: 599 # Check frames using the function's details. 600 601 fn = node.unit 602 nparams = len(fn.positional_names) 603 ndefaults = len(fn.defaults) 604 605 fn.body_block = self.new_block() 606 607 # Check the number of parameters and defaults. 608 609 self.new_op(CheckFrame((nparams, ndefaults))) 610 if ndefaults > 0: 611 self.new_op(LoadFunction(fn)) 612 self.new_op(FillDefaults((nparams, ndefaults))) 613 614 # Produce the body. 615 616 self.set_block(fn.body_block) 617 618 extend = ExtendFrame() 619 self.new_op(extend) 620 621 # For functions with star parameters, make a special list for the 622 # extra arguments and re-map the parameter. 623 624 if fn.has_star: 625 self.new_op(CopyExtra(nparams)) 626 627 # Ensure that the star parameter has a slot in the frame. 628 629 self.new_op(CheckExtra(nparams)) 630 self.new_op(StoreTemp(nparams)) 631 632 self.dispatch(node.code) 633 634 if not isinstance(self.last_op(), Return): 635 self.dispatch(compiler.ast.Name("None")) 636 self.new_op(StoreResult()) 637 self.new_op(Return()) 638 639 # Make sure that enough frame space is reserved from the start. 640 641 self.set_frame_usage(node, extend) 642 643 def visitGlobal(self, node): pass 644 645 def visitImport(self, node): pass 646 647 def visitKeyword(self, node): pass 648 649 def visitLambda(self, node): 650 651 """ 652 Lambda functions can be represented as globally defined functions 653 provided they do not define any default parameter values, since these 654 may defined in a non-global scope. 655 656 Where defaults are defined, an object must be created and its content 657 defined: the callable member of the object's structure must be set to 658 the lambda function definition; each default must be attached to the 659 object as an attribute, as is the case with normal functions and 660 methods. 661 """ 662 663 # Produce the reference to this function when visiting this node from 664 # outside. 665 666 if self.unit is not node.unit: 667 fn = node.unit 668 ndefaults = len(fn.defaults) 669 temp = self._generateFunctionDefaults(fn) 670 671 if ndefaults > 0: 672 self.new_op(LoadConst(fn)) 673 else: 674 self.new_op(LoadFunction(fn)) 675 676 # Populate the new object required for the function. 677 678 if temp is not None: 679 self.new_op(LoadCallable()) 680 self.new_op(temp) 681 self.new_op(StoreCallable()) 682 683 self.new_op(temp) 684 #self.discard_temp(temp) 685 686 # Visiting of the code occurs when get_code is invoked on this node. 687 688 else: 689 # Check frames using the function's details. 690 691 fn = node.unit 692 nparams = len(fn.positional_names) 693 ndefaults = len(fn.defaults) 694 695 fn.body_block = self.new_block() 696 697 # Check the number of parameters and defaults. 698 699 self.new_op(CheckFrame((nparams, ndefaults))) 700 if ndefaults > 0: 701 self.new_op(LoadTemp(0)) # context provides storage 702 self.new_op(FillDefaults((nparams, ndefaults))) 703 704 # Produce the body. 705 706 self.set_block(fn.body_block) 707 708 extend = ExtendFrame() 709 self.new_op(extend) 710 711 self.dispatch(node.code) 712 713 self.new_op(StoreResult()) 714 self.new_op(Return()) 715 716 # Make sure that enough frame space is reserved from the start. 717 718 self.set_frame_usage(node, extend) 719 720 def visitModule(self, node): 721 extend = ExtendFrame() 722 self.new_op(extend) 723 self.dispatch(node.node) 724 self.set_frame_usage(node, extend) 725 726 # Statements. 727 728 def visitStmt(self, node): 729 730 "Process the collection of statements provided by 'node'." 731 732 for n in node.nodes: 733 734 # Process the statement. 735 736 self.dispatch(n) 737 738 # Discard temporary storage. 739 740 if self.temp_positions: 741 #print "Had temp", self.temp_positions 742 self.temp_positions = set() 743 744 # Prevent incorrect optimisation by resetting the optimiser after 745 # each statement. 746 747 self.optimiser.reset() 748 749 def visitAssert(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Assert") 750 751 def visitBreak(self, node): 752 next_block, exit_block = self.get_loop_blocks() 753 self.new_op(Jump(exit_block)) 754 755 def visitContinue(self, node): 756 next_block, exit_block = self.get_loop_blocks() 757 self.new_op(Jump(next_block)) 758 759 def visitDiscard(self, node): 760 self.dispatch(node.expr) 761 self.optimiser.optimise_unused_results() 762 763 def visitFor(self, node): 764 next_handler_block = self.new_block() 765 end_handler_block = self.new_block() 766 exit_block = self.new_block() 767 next_block = self.new_block() 768 else_block = self.new_block() 769 770 # Get the "list" to be iterated over, obtain its iterator. 771 772 self._startCallFunc() 773 self.dispatch(node.list) 774 self._generateAttr(node, "__iter__", self.attribute_load_instructions) 775 temp_target, target, temp_context = self._generateCallFunc([], node) 776 self._doCallFunc(temp_target, target) 777 self._endCallFunc(temp_target, target, temp_context) 778 779 # Use a long-lasting temporary storage slot, since any result from the 780 # __iter__ method will not remain around for long. 781 782 temp_iterator = self.get_temp() 783 784 # In the loop... 785 786 self.set_block(next_block) 787 788 # Handle exceptions when calling "next"... 789 790 self.new_op(PushHandler(next_handler_block)) 791 792 # Use the iterator to get the next value. 793 794 self._startCallFunc() 795 self.new_op(temp_iterator) 796 self._generateAttr(node, "next", self.attribute_load_instructions) 797 temp_target, target, temp_context = self._generateCallFunc([], node) 798 self._doCallFunc(temp_target, target) 799 self._endCallFunc(temp_target, target, temp_context) 800 801 # Record the value to be assigned. 802 803 self.record_value() 804 805 # Skip the handler where the call was successful. 806 807 self.new_op(PopHandler()) 808 self.new_op(Jump(end_handler_block)) 809 810 # Enter the exception handler. 811 812 self.set_block(next_handler_block) 813 self.new_op(PopHandler()) 814 815 # Test for StopIteration. 816 817 self.load_builtin("StopIteration", node) 818 self.new_op(CheckException()) 819 if node.else_ is not None: 820 self.new_op(JumpIfTrue(else_block)) 821 else: 822 self.new_op(JumpIfTrue(exit_block)) 823 824 # Re-raise the exception otherwise. 825 826 self.new_op(RaiseException()) 827 828 # After the handler, clear the exception. 829 830 self.set_block(end_handler_block) 831 832 # Assign to the target. 833 834 self.dispatch(node.assign) 835 self.discard_value() 836 837 # Process the body with the current next and exit points. 838 839 self.add_loop_blocks(next_block, exit_block) 840 self.dispatch(node.body) 841 self.drop_loop_blocks() 842 843 # Repeat the loop. 844 845 self.new_op(Jump(next_block)) 846 847 # Produce the "else" section. 848 849 if node.else_ is not None: 850 self.set_block(else_block) 851 self.new_op(ClearException()) 852 self.dispatch(node.else_) 853 854 # After the loop... 855 856 self.set_block(exit_block) 857 858 else: 859 # After the loop... 860 861 self.set_block(exit_block) 862 self.new_op(ClearException()) 863 864 # Compilation duties... 865 866 self.discard_temp(temp_iterator) 867 868 def visitIf(self, node): 869 first = 1 870 next_block = None 871 exit_block = self.new_block() 872 873 clauses = node.tests + [(None, node.else_)] 874 875 for clause in clauses: 876 test, body = clause 877 if body is None: 878 break 879 880 if not first: 881 self.new_op(Jump(exit_block)) # finish last body 882 self.set_block(next_block) # start next test 883 next_block = None 884 885 if test is not None: 886 self.dispatch(test) 887 888 temp = self.optimiser.optimise_temp_storage() 889 self._generateTestBoolean(node, temp) 890 891 next_block = self.new_block() 892 self.new_op(JumpIfFalse(next_block)) 893 894 self.dispatch(body) 895 first = 0 896 897 if next_block is not None: 898 self.set_block(next_block) 899 900 self.set_block(exit_block) 901 902 def visitPass(self, node): pass 903 904 def visitPrint(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Print") 905 906 def visitPrintnl(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Printnl") 907 908 def visitRaise(self, node): 909 # NOTE: expr1 only => instance provided 910 self.dispatch(node.expr1) 911 912 if node.expr2 is not None: 913 temp = self.optimiser.optimise_temp_storage() 914 915 self.dispatch(node.expr2) 916 temp_arg = self.optimiser.optimise_temp_storage() 917 918 self._startCallFunc() 919 self.new_op(temp_arg) 920 self.new_op(StoreFrame(0)) 921 self._endCallFuncArgs(1) 922 self._doCallFunc(temp) 923 self._endCallFunc(temp) 924 925 self.discard_temp(temp_arg) 926 927 self.new_op(StoreException()) 928 self.new_op(RaiseException()) 929 930 def visitReturn(self, node): 931 if node.value is not None: 932 self.dispatch(node.value) 933 else: 934 self.dispatch(compiler.ast.Name("None")) 935 936 self.new_op(StoreResult()) 937 938 if self.in_exception_handler: 939 self.new_op(ClearException()) 940 941 self.new_op(Return()) 942 943 def visitTryExcept(self, node): 944 exit_block = self.new_block() 945 else_block = self.new_block() 946 handler_block = self.new_block() 947 948 self.add_exception_blocks(handler_block, exit_block) 949 950 # Try... 951 # Produce the code, then jump to the exit. 952 953 self.new_op(PushHandler(handler_block)) 954 self.dispatch(node.body) 955 self.new_op(PopHandler()) 956 957 if node.else_ is not None: 958 self.new_op(Jump(else_block)) 959 else: 960 self.new_op(Jump(exit_block)) 961 962 # Start of handlers. 963 964 self.set_block(handler_block) 965 self.new_op(PopHandler()) 966 967 for name, assignment, handler in node.handlers: 968 next_block = self.new_block() 969 970 # Test the given exception against the current exception. 971 972 if name is not None: 973 self.dispatch(name) 974 975 self.new_op(CheckException()) 976 self.new_op(JumpIfFalse(next_block)) 977 978 # Handle assignment to exception variable. 979 980 if assignment is not None: 981 self.new_op(LoadException()) 982 983 # Record the value to be assigned. 984 985 self.record_value() 986 self.dispatch(assignment) 987 self.discard_value() 988 989 # Produce the handler code, then jump to the exit. 990 991 self.in_exception_handler = 1 992 self.dispatch(handler) 993 self.in_exception_handler = 0 994 995 self.new_op(Jump(exit_block)) 996 997 self.set_block(next_block) 998 999 # Unhandled exceptions. 1000 1001 self.new_op(RaiseException()) 1002 1003 # Optional else clause. 1004 1005 if node.else_ is not None: 1006 self.set_block(else_block) 1007 self.dispatch(node.else_) 1008 1009 # Clear the exception. 1010 1011 self.set_block(exit_block) 1012 self.new_op(ClearException()) 1013 self.drop_exception_blocks() 1014 1015 def visitTryFinally(self, node): 1016 1017 """ 1018 Add finally handler, potentially as an exception handler. 1019 Generate body, potentially changing return statements so that they do 1020 not return immediately. 1021 Generate handler, removing the handler from the active handler list, 1022 adding instructions which raise active exceptions. 1023 """ 1024 1025 raise TranslationNotImplementedError(self.module.full_name(), node, "TryFinally") 1026 1027 def visitWhile(self, node): 1028 exit_block = self.new_block() 1029 next_block = self.new_block() 1030 else_block = self.new_block() 1031 1032 self.set_block(next_block) 1033 self.dispatch(node.test) 1034 if node.else_ is not None: 1035 self.new_op(JumpIfFalse(else_block)) 1036 else: 1037 self.new_op(JumpIfFalse(exit_block)) 1038 1039 self.add_loop_blocks(next_block, exit_block) 1040 1041 self.dispatch(node.body) 1042 self.new_op(Jump(next_block)) 1043 1044 if node.else_ is not None: 1045 self.set_block(else_block) 1046 1047 self.dispatch(node.else_) 1048 1049 self.set_block(exit_block) 1050 1051 self.drop_loop_blocks() 1052 1053 def visitWith(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "With") 1054 1055 def visitYield(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Yield") 1056 1057 # 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